I had a similar issue with the main quests.
I knew where it was, but the quest icon wasn't showing above the persons head because of a graphics glitch.
I logged out and back in (this was 4am EST, so I was able to do that), and the quest showed up on the main map, but couldn't see it on the person.

Anyways, i ended up having to rotate the camera in a really weird angle from a certain spot and it showed up and was able to do it.
But the moral here, is check the maps thoroughly. You may have to go to each zone to see because they don't show up when scanning the maps from other zones.
The recommendations list also doesn't show anything from outside your zone (which is dumb)

Basically the progression for the quests at that point is... at level 15 you get airship pass, need to visit all 3 cities, 3 dungeons between 15 and 20, Ifrit at level 20. Then you get your Grand Company/Chocobo quests after Ifrit fight. You should be able to trace back where you are by what you haven't done.
I was actually just thinking this today though. There are so many main storyline quests, what happens when you simply forget to engage the NPC for the next quest, and you go off to do something for a few hours/days... there really should be a way to tell you where to go for your next main story quest, because it honestly could be anywhere.

Basically the progression for the quests at that point is... at level 15 you get airship pass, need to visit all 3 cities, 3 dungeons between 15 and 20, Ifrit at level 20. Then you get your Grand Company/Chocobo quests after Ifrit fight. You should be able to trace back where you are by what you haven't done.
I was actually just thinking this today though. There are so many main storyline quests, what happens when you simply forget to engage the NPC for the next quest, and you go off to do something for a few hours/days... there really should be a way to tell you where to go for your next main story quest, because it honestly could be anywhere.

Yeah that's what the /recommended feature is that I mention. It will show you all the quests in the area that you can do at your level with priority going to a story quest.

What I really hate about this story questing is how you can be roadblocked from progressing any further due to requiring to find a party. Been trying to get past Lord of the Inferno for two days now using duty finder.